Safety-brake for elevators.



No.'885,560. PATENTED APR. 21.*1908. Y E. A. WURTHINGTON.

SAFETY BRAKE FOR ELEVATORS.

APPLIOATION FILED JAN. 3o. 1.9m.

2 SHEETS-SHEET 1.

No. 885,560. PATENTED APR. 21, 1908. E. A. WORTHINGTON.

SAFETY BRAKE POR BLEVATORS.

APPLIOATION FILED JAN.ao,19o7.

2 SHEETS-SHEET 2.

rus Nonni: PETER: co., wAsmNoroN. n. c:A

UNITED sTArns iig/grani onirica.

EDWARD A. WORTHINGTON, OF LINCOLN, NEBRASKA.

SAFETY-BRAKE FOR ELEVATORS.

To all whom it may concern.'

Be it known that I, EDWARD A. VoR'rn- INGTON, a citizen of the UnitedStates of America, residing at Lincoln, in the county of Lancaster andState of Nebraska, have invented new and useful Improvements inSafety-Brakes for Elevators, of which the following is a specification.

This invention relates to safety brakes designed for use in connectionwith elevators, hoists and lifts for automatically arrestingl thedownward motion of the car and bringing the same to a gradual andcomplete stop in the event of accidents, such as the breaking of thehoisting rope or cable.

The ,main object of the invention is to provide a safety brake mechanismwhich will be automatically thrown into operation when the car starts tomove downward by gravity at a speed in excess of the established maximumspeed to stop the descent of the car, and to perform its operationwithout objectionable jerks or jars promptly before the car acquiresmuch momentum.

A further object is to provide an improved type of safety brakemechanism whereby the speed of the carin either direction will beindicated and controlled, which will be easily and yet quickly ,set intooperation when the maximum speed is exceeded, and which may be reset ina convenient manner to restore the parts to normal condition.

In the accompanying drawings,-Figure 1 is a view in elevation, partly insection, of the top of an elevator car equipped with my invention,showing the parts in normal position. Fig. 2 is a vertical longitudinalsection through the friction brake gearing for stopping the revolublebrake element. Fig. 3 is a detail section on line 3`3 of Fig. 1.

In the drawings, 1 represents the top of an elevator car, 2 a barvertically arranged in the elevator shaft and provided with rack teeth3, and 4 a frame arranged upon the top of the'car to support the brakemechanism.

The bar 2 and its teeth 3 constitute a stationary brake member, withwhich coperates a revoluble brake member 5, comprising a Worm meshing`with said teeth. The worm is provided at its upper end with a journal 6having bearing in the upper end of the frame 4 and at its lower end witha jour- Specication of Letters Patent.

Application filed January 30, 1907.

Patented April 21, 1908.

Serial No. 354,878.

nal 7, which is chambered to receive the upper end of a shaft Sjournaled at its lower end in the car roof 1. The journal 7 turns uponthe shaft 8 which is normally stationary and is provided with teeth 9 toform a relatively stationary clutch member for cooperation with amovable clutch member. 10 feathered to slide on and rotate with theshaft S.

A sprocket wheel 11 is fixed on the shaft S, and surrounding said shaftbetween said wheel and the clutch member 10 is a coiled spring 12 whichtends to throw said clutch member into engagement with the clutch member9. The clutch member 10 is formed with a flange 13 and is engaged by theyoked outer or free end of a clutch-controlling lever 14, which, in thenormal operation of the parts, bears upon said flange and holds themember 10 out of engagement with the member 9.

The lever 14 is pivoted at 15 to a bearing 16 in which is ournaled thelower end of a centrifugal governor shaft or stem 17, journaled at itsupper end in the top of the frame 4, which shaft carriesa sprocket wheel18 connected with a sprocket wheel 19 on the journal 6 by a chain 20,whereby the governor is continuously driven by the worm 5 during themotion of the car. The governor is provided with the usual weighted arms21 connected by links 22 to a sliding sleeve 23 operatively connectedwith one end of a latch controlling lever 24, the opposite end of whichis pivoted at 25 to an extension from the frame 4. On the pivot 25 isalso pivotally mounted at its vertex portion a segmental latch 26, oneend of the curved rim of which forms a locking member to engage alocking shoulder 27 on the lever 14, while the opposite end of said rimis formed with a .series of openings 2S for adjustable connection withthe lever 24 through the medium of a bolt or other suitable fastening29, whereby said latch may be adjusted for engagement with the shoulder27 to hold the lever 14 down against the pressure of the springT 12 toregulate the distance of clutch member 10 from clutch member 9 to varythe time interval of throvng said clutch members into engagement, thusregulating the quickness of action of the brake mechanism.

A vertical power transmitting shaft 30 is Y journaled in the frame androof 1 and carries a sprocket wheel 31 connected with sprocket wheel 1lby a chain 32. The lower end of said shaft 30 is provided with a crankwheel 33 by which the operator from within the car may reset or returnthe parts of the brake mechanism to normal position, as hereinafterdescribed. On the upper end of shaft 30 is a beveled pinion 34 meshingwith a beveled gear 35 on a horizontal shaft 36. Keyed on said shaft arestationary brake disks or wheels 37 and 38 which cooperate withinterposed relatively movable or slidable brake disks or wheels 37 and38 connected for movement in unison by rods or bolts 39, the opposingfaces of said wheels being trued for anY effective frictionalengagement. The disks 37 and 38 are formed with axial openings vfor thepassage of the shaft 36, and are adapted to receive motion from theshaft through an interposed wheel or disk 40, slidably engaging the rodsor bolts 39 and having a central screw-threaded opening engaging thethreaded portion 41 of said shaft, whereby reverse movements of theshaft will .move the disk 4() in one direction or the other, the saiddisk thus operating in the nature of a traveling nut to communicatemotion to the traveling brake disks. Surrounding the bolts or rods 39between the opposite sides of the disk 40 and the respective brake disks37 and 38 are coiled cushioning or resistance springs 42. These springsform a yielding connection between the disk or nut 40 and the twomovable brake disks by which, when the disk 40 is moved in one directionor the other by the action of the shaft 36, motion will be communicatedto the movable disks to throw disk 37 into engagement with disk 37 ordisk 38 into engagement with disk 38.

When either of said movable disks comes into Contact with itscooperating stationary disk the braking pressure of said movable diskwill be gradually and yieldingly transmitted to the stationary diskthrough the resistance of the springs, which must be gradually overcomebefore the full braking pressure is applied, thus securing a quick andeffective braking action without jar or strain on the brake mechanism.The disks 37', 38 and 40 are provided with projections 43 enteringgrooves 44 in the framework, thus allowing said disks to slide withoutpermitting them to rotate, as will be readily understood. The disk 40carries a pointer 45 movable in a slot in the framework and top of thecar and projecting at its lower end into the latter, so that theoperator of the car may at all times determine the position of said diskand the condition of the brake mechanism, whereby if the maximunrspeedof the car is exceeded and the brake mechanism is thrown into operationthe operator, warned by the movement of the pointer, may throw 0H thepower or reduce the speed of the car.

Connected with the lever 14 is a resetting rod 46, which projectsdownward into the car within convenient reach of the operator, to permitsaid lever, after operation of the brake mechanism, to be drawn down toretract the clutch member 13 and bring the shoulder 27 in position to beagain engaged by the latch 26.

Fig. 1 shows the normal position of the parts, from which it will beapparent that the worm or revoluble brake element 5 will be revolved inone direction or the other as the car moves up or down, and the governorwill be continuously operated thereby, the remaining parts of the brakemechanism being inactive during normal conditions. lf the hoisting ropeshould break and the car begin to descend by gravity, as soon as thenormal maximum speed is exceeded the lever 24 will be swung up by theaction of the governor to retract the latch 26, whereby the clutchmember 13 will be thrown into engagement with the clutch member 7, thusconnecting shaft S with the worm 5 to turn therewith and effectingrotation of the shaft 36 through the intervening gearing. The shaft 36will be rotated in one direction or the other according to the directionof rotation of the worm 5 in the up or down motion of the car when thegearingis set into operation by the governor by the movement of the carat excess speed under normal conditions or its dropping through thebreakage of the hoisting cable. As a result, nut or disk 40 will bemoved in one direction or the other to shift the movable brake disks, tobring brake disk 37 into engagement with disk 37 or disk 38 intoengagement with disk 38. i/Vhen the acting braking disks come intoengagement gradually through the resisting action of the springsdescribed, the movement of the shaft 36 will be checked until it isbrought to a complete stop, whereupon such part of the brake gearingwill similarly reduce the speed and stop the motion of the shaft S andworm 5, which latter being in mesh with the teeth 3 will, when broughtto a state of rest, stop the further movement of the car. It will beapparent that the brake mechanism will thus operate to stop the carpromptly without jolts or jars, thus preventing any liability ofderangement or breakage of the brake gearm0'.

zplhe construction of the gearing is such that it will operate when themaximum speed of the car is exceeded either in its up or down movement,thus insuring the safety under all conditions, the operator beingenabled by the movement of the pointer 45 when the clutches are throwninto gear to determine the condition of affairs and throw off power orcheck the speed of the car at once.

By adjusting the latch 26 the speed of operation of the clutch mechanismmay be regulated in an obvious manner, and by means of the rod 46 theclutch l0 may be restored to normal osition to reset the apparatus, ashereinbe'ore described. I

The advantages of the improved mechanism will be readily understood andappreciated and it'will be seen that the invention provides a simple andreliable type of brake gear by which danger of accidents in theoperation of an elevator or similar contrivance equipped with theinvention will be prevented.

Having thus described the invention, what is claimed as new, is:-

v 1. In an automatic elevator brake, the combination with a car,'and astatienar-y brake element, of a coacting revoluble brake element on thecar, a governor operated by the revoluble brake element, brakemechanism, gearing including clutch mechanism for connecting said brakemechanism with the revoluble brake element, and means controlled by thegovernor for throwing the clutch mechanism into action.

2. In an automatic elevator brake, the combination of a car, and astationary brake element, of a revoluble brake element on the, car, agovernor operated by the movement of the revoluble brake element, brakemechanism including a screw shaft and brake devices o erated thereby,gearing for driving the s aft, clutch mechanism for connecting saidgearing with the revoluble brake element, and means controlled by thegovernor for holding the clutch mechanism out of action and throwingthesame into action.

.3. In an automatic elevator brake, the combination with a car, and astationary brake element, of a revoluble brake element on the car, agovernor operated by the revoluble brake element, friction brakemechanism, a screw shaft for operating said brake mechanism, gearing fordriving said shaft from the revoluble brake element, clutch gearing forconnecting said gearing with the revoluble brake element, and means fornormally holding said clutch gearing out of aetion, said means beingcontrolled by the governor and adapted to be thrown into action thereby.p

4. In an automatic brake for elevators, the combination with a car, anda stationary brake element, of a revoluble brake element on the car, agovernor driven by the revoluble brake element, friction brakemechanism, a screw shaft for operating the same, means for yieldinglyopposing a resistance to the action of the brake mechanism, gearing fordriving the shaft from the revoluble brake element, and a clutchcontrolled by the governor for throwing said gearing into connectionwith the revoluble brake element.

5. In an automatic brake for elevators, the combination with a car, anda stationary brake element, of a revoluble brake element on the car, agovernor operated by the revoluble brake element, stationary frictiondisks, movable friction disks to engage the same, means including ascrew shaft for operating the movable disks, gearing for driving themovable disks from the revoluble brake element, and means controlled bythe governor for throwing said gearing into action.

(5. ln an automatic brake for elevators, the combination with a car, anda stationary brake element, of a revoluble brake element on the car, agovernor driven by said revolu-4 ble brake element, a screw shaft, brakedisks fixed thereto, connected movable brake disks to engage said fixedbrake disks, a gear nut operated by the screw shaft to operate themovable brake disks, gearing for driving the screw shaft, and meanscontrolled by the governor for throwing said gearing into connectionwith the revoluble brake element.

7. ln an automatic brake for elevators, the combination with a car, anda stationary brake element, of a cooperating revoluble brake element, agovernor driven by the revoluble brake element, a drive shaft, a brakemechanism iu gear with and operated by said shaft, cooperating clutchmembers on the revoluble brake element and shaft, one of said membersbeing spring actuated, a controlling lever for holding the springactuated clutch member out of action, said lever being provided with alatch element, a second lever controlled and operated by the governor,and an adjustable latch device operated by said second lever and adaptedto engage the latch element on the first named lever.

S. In an automatic brake for elevators, a car, a stationary brakemember, a coperating revoluble brake member, a governor driven by therevoluble brake member, a screw shaft, brake disks fixed to the shaft,cooperating sliding brake disks, connections between the sliding disks,a nut arranged between the sliding disks for operation by the shaft,springs between the n'ut and sliding disks and supported by saidconnections, gearing for operating the screw shaft from the revolublebrake member, and means controlled by the governor for connecting saidgearing with the revoluble brake member.

9. ln an automatic brake for elevators, a car, a stationary brakeelement, a coperating revoluble brake element on the car, a screw shaft,stationary brake disks carried thereby,4 slidablc brake disks tocoperate therewith, means operated by the shaft for sliding said disks,cushioning means between the sliding disks and operating means, and

`means controlled by the governor for operating the shaft from therevoluble brake element. y

10. ln an automatic elevator brake, a stationary brake member, acoacting normally movable brake member on the car, a governor driven bythe movable brake element, brake mechanism adapted to be thrown-intoaction by the governor to stop the operation otl the movable brakemember, said brake mechanism including an operating member,

and an indicator actuated by said operating member.

11. In an automatic elevator brake, the combination with a car, and astationary brake element, of a coacting revoluble brake elementon thecar in gear with and driven by said stationary brake element, a governordirectly driven by the revoluble brake element, brake mechanismcontrolling the revoluble brake element, gearing connecting said brakemechanism with the revoluble brake element, said gearing being normallyinoperative, and means controlled by the governor for rendering said`gearing operative.

12. In an automatic brake mechanism, a stationary rack, a worm gear onthe car constantly driven by the rack, a governor operated by the wormgear, a brake mechanism for arresting the motion of the worm gear,normally inoperative gearing for driving said-mechanism from the wormgear, and means controlled by the governor for rendering said gearingoperative.

13. In an automatic brake for elevators, the combination with a car, anda stationary brake element, of a coacting revoluble brake element on thecar, a governor operated by said revoluble brake element, gearingnormally out of connection with the revoluble lbrake element, a brakemechanism driven by said gearing, said mechanism including sets ofdevices for frictional engagement upon reverse movements of the gearingto arrest the movement of the revoluble brake element on either the upor down movement of the car, and means controlled by the governor forthrowing said gearing into connection with the revoluble brake element.

14. ln an automatic brake for elevators, the combination with a car, anda stationary brake element, of a revoluble brake element on the car, agovernor driven by said revoluble brake element, a screw shaft, brakedevices, a gear nut operated by the screw shaft to throw said brakedevices into and out of action, gearing for driving the screw shaft,means controlled by the governor for throwing said gearingl intoconnection with the revoluble brake element, and an indicator operatedby the gear nut.

15. In an automatic brake mechanism for elevators, the combination witha car, and a stationary brake element, of a coacting revoluble brakeelement, a governor driven by the revoluble brake element, gearingadapted to be driven by the revoluble brake element, means controlled bythe governor for throwing said gearing into connection with therevoluble brake element, and a brake mechanism actuated by said gearingfor arresting the motion of the revoluble gear element, said gearingcomprising stationary braking elements and relatively movable brakingelements operative in reverse directions to respectively engage saidstationary braking elements, combined with means for opposing a yieldingresistanceto the movement of said movable braking elements.

In testimony whereof, l a'HiX my signature in presence of two witnesses.

'EDWARD A. VVORTHINGTON.

Vitnesses C. H. BAR-srow, NELL G. ANDERSON.

